Cooling device

ABSTRACT

Provided is a cooling device capable of appropriately cooling a cold insulator and keeping the cold insulator at an appropriate temperature. The cooling device includes a cooling portion that has an inner space storing an object, a measurement means of measuring a temperature corresponding to a temperature of the object stored in the inner space, and a control means of controlling a temperature of the inner space based on a measurement result by the measurement means, in which, based on the measurement result, the control means performs control to change the temperature of the inner space from a first setting temperature that is lower than a temperature at which the object in a liquid phase starts to be solidified to a second setting temperature that is higher than the first setting temperature and lower than a melting temperature of the object.

TECHNICAL FIELD

The present invention relates to a cooling device.

BACKGROUND ART

In order to keep quality of foodstuffs, pharmaceuticals, and the like, a technique of keeping such cold insulation objects at a fixed temperature has been recently required.

This application claims priority based on Japanese Patent Application No. 2017-253662 filed in Japan on Dec. 28, 2017, the content of which is incorporated herein.

Here, the “fixed temperature” that is required varies depending on a cold insulation object. For example, when a cold insulation object is a pharmaceutical, it is required to keep the cold insulation object cold at 2° C. to 8° C. Moreover, when a cold insulation object is fresh fish and shellfish, the cold insulation object is preferably kept cold at a temperature different from that of the pharmaceutical.

A cold insulator for keeping a cold insulation object cold at a temperature different from “0° C.” that is a melting point of ice as described above is conventionally known (for example, refer to PTL 1). A cold insulator described in PTL 1 has a melting temperature of 0 to 10° C. and enables to suitably keep a cold insulation object at a desired temperature. For example, a cold insulator with a melting temperature of 5° C. is able to be suitably used for keeping a cold insulation object, which is required to be kept cold at 2° C. to 8° C., cold.

CITATION LIST Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No. 2007-163045

Technical Problem

When being used, the cold insulator described in PTL 1 needs to be frozen in a freezer or the like and have a phase changed to a solid phase in advance. For example, when the cold insulator is frozen in the freezer, the cold insulator has the phase changed to the solid phase and is then cooled to a temperature in the freezer. Thus, even in a case of the cold insulator with the melting temperature of 5° C., when the temperature in the freezer is −5° C., the cold insulator whose phase is changed to the solid phase (frozen) is also cooled to −5° C.

In a case where a cold insulation object required to be kept cold at, for example, 2° C. to 8° C. is kept cold, the cold insulator cooled to −5° C. as described above is not suitable because the temperature thereof is too low. Thus, there is a problem that the cold insulator is difficult to be used until the temperature of the cold insulator reaches a suitable temperature after the cold insulator is taken out from the freezer.

The invention is made in view of such circumstances and aims to provide a cooling device capable of appropriately cooling a cold insulator and keeping the cold insulator at an appropriate temperature.

Solution to Problem

In order to solve the aforementioned problem, an aspect of the invention provides a cooling device including: a cooling portion that has an inner space storing an object; a measurement means of measuring a temperature corresponding to a temperature of the object stored in the inner space; and a control means of controlling a temperature of the inner space based on a measurement result by the measurement means, in which, based on the measurement result, the control means performs control to change the temperature of the inner space from a first setting temperature that is lower than a temperature at which the object in a liquid phase starts to be solidified to a second setting temperature that is higher than the first setting temperature and lower than a melting temperature of the object.

In an aspect of the invention, a configuration may be such that, when detecting solidification heat and the melting temperature of the object based on the measurement result and then further detecting that the measurement result reaches a reference temperature that is a temperature lower than the melting temperature, the control means performs control to change the temperature of the inner space from the first setting temperature to the second setting temperature.

In an aspect of the invention, a configuration may be such that, when detecting the melting temperature based on the measurement result and then further detecting that the measurement result reaches a reference temperature that is a temperature lower than the melting temperature, the control means performs control to change the temperature of the inner space from the first setting temperature to the second setting temperature.

In an aspect of the invention, a configuration may be such that the control means acquires the temperature of the object per unit time from the measurement means and detects the solidification heat based on a change amount of the measurement result per unit time.

In an aspect of the invention, a configuration may be such that the control means acquires the temperature of the object per unit time from the measurement means and detects the melting temperature based on a change amount of the measurement result per unit time.

In an aspect of the invention, a configuration may be such that the control means is able to change the unit time.

In an aspect of the invention, a configuration may be such that the cooling portion has a placement portion on which the object is placed, and the measurement means is a temperature sensor of a contact type that is provided in the placement portion.

In an aspect of the invention, a configuration may be such that the temperature sensor has a plurality of probes, and the plurality of probes are provided in the placement portion.

In an aspect of the invention, a configuration may be such that the measurement means is a temperature sensor of a non-contact type that is provided in the inner space.

In an aspect of the invention, a configuration may be such that the cooling portion has a placement portion on which the object is placed, the placement portion has a weighing means of weighing mass of the object, and, based on an expected cooling time per unit mass of the object, which is stored in advance, and a weighing result of the weighing means, the control means approximates an expected cooling time of a whole of the object stored in the inner space.

In an aspect of the invention, a configuration may be such that the inner space is spatially divided into a first space and a second space that is different from the first space, and has a moving means of moving the object from the first space to the second space, the first space includes the measurement means and is provided so as to be able to change a temperature of the first space between the first setting temperature and the second setting temperature, and the second space is set to have a third setting temperature that is higher than the first setting temperature and lower than the melting temperature of the object.

In an aspect of the invention, a configuration may be such that the cooling portion has a cooling means of cooling the inner space, and the cooling means is a cooling unit of a compressor system.

In an aspect of the invention, a configuration may be such that the cooling portion has a cooling means of cooling the inner space, and the cooling means is a cooling unit of a Peltier system.

In an aspect of the invention, a configuration may be such that an alarm portion that outputs alarm sound is included and the control means changes the temperature of the inner space to the second setting temperature and then causes the alarm portion to output the alarm sound.

In an aspect of the invention, a configuration may be such that an alarm portion that outputs alarm sound is included, and the control means changes the temperature of the inner space to the second setting temperature, and after the temperature of the inner space reaches the second setting temperature, the control means causes the alarm portion to output the alarm sound.

In an aspect of the invention, a configuration may be such that an alarm portion that outputs alarm sound is included, and the control means changes the temperature of the inner space to the second setting temperature, and after the temperature of the object reaches the second setting temperature, the control means causes the alarm portion to output the alarm sound.

Advantageous Effects of Invention

According to the invention, a cooling device capable of appropriately cooling a cold insulator (object) and keeping the cold insulator at an appropriate temperature is able to be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic perspective view illustrating a cooling device 1 of a first embodiment.

FIG. 2 is a schematic sectional view illustrating the cooling device 1.

FIG. 3 is an explanatory view for explaining control of an inner space S based on a temperature of a cold insulator I.

FIG. 4 is an explanatory view for explaining control of the inner space S based on the temperature of the cold insulator I.

FIG. 5 is an explanatory view for explaining control of the inner space S based on the temperature of the cold insulator I.

FIG. 6 is an explanatory view for explaining control of the inner space S based on the temperature of the cold insulator I.

FIG. 7 is an explanatory view of a cooling device 2 according to a second embodiment.

FIG. 8 is an explanatory view of a cooling device 3 according to a third embodiment.

FIG. 9 is an explanatory view of a cooling device 4 according to a fourth embodiment.

FIG. 10 is an explanatory view of a cooling device 5 according to a fifth embodiment.

FIG. 11 is an explanatory view of the cooling device 5 according to the fifth embodiment.

FIG. 12 is an explanatory view of a cooling device 6 according to a sixth embodiment.

DESCRIPTION OF EMBODIMENTS First Embodiment

A cooling device according to a first embodiment of the invention will be described below with reference to FIGS. 1 to 12. Note that, in all the following drawings, components may be illustrated at different dimensional scales, ratios, or the like in order to make the drawings easy to see.

FIG. 1 is a schematic perspective view illustrating a cooling device 1 of the present embodiment. FIG. 2 is a schematic sectional view illustrating the cooling device 1. The cooling device 1 is a device capable of appropriately cooling a cold insulator (object) I to be cooled and keeping the cold insulator I at an appropriate temperature.

In the cooling device 1 of the present embodiment, the cold insulator I using a phase change material that is liquid at a normal temperature and is solid when being cooled is adopted as an object to be cooled. For example, the cold insulator I adopts a form in which the phase change material is liquid-tightly sealed in a pouch-like container.

As the phase change material used for the cold insulator I, a commonly known material is able to be used. Examples thereof include a solution that contains, as a main ingredient, one or more salts selected from a group consisting of a quaternary ammonium salt, a potassium salt, and a sodium salt, and a material obtained by adding an additive, which aims to suppress excessive cooling, to such a solution. The main ingredient may be a material that forms a clathrate hydrate.

The “clathrate hydrate” is a crystal in which another substance (molecule, salt) enters a basket-shaped structure of a water molecule formed by hydrogen bond. For example, it is known that a solution of a quaternary ammonium salt of predetermined concentration forms the clathrate hydrate when being cooled. When forming the crystal of the basket-shaped structure, the clathrate hydrate absorbs heat similarly to storage of latent heat when the phase change material changes in a phase. Thus, the clathrate hydrate is able to be used similarly to the phase change material.

An example of the additive that aims to suppress excessive cooling includes sodium tetraborate. For example, in a case where tetrabutylammonium bromide (TBAB) is used as the quaternary ammonium salt, when the TBAB is used by adding sodium tetraborate to 40 mass % TBAB solution (hereinafter, TBAB solution) by 2% of mass of the TBAB solution, excessive cooling of a resultant solution is able to be suppressed.

A material widely known as a latent heat storage material is also able to be used as the phase change material.

As illustrated in FIGS. 1 and 2, the cooling device 1 of the present embodiment has a cooling portion 10, a temperature sensor (a measurement means) 20, and a control unit (a control means) 30.

The cooling portion 10 has an inner space S in which the cold insulator I to be cooled is stored. The cooling portion 10 has a device main body 101, a door member 102, and a cooling unit (a cooling means) 108.

The device main body 101 has the inner space S connected to an outside via an opening 101 a. The door member 102 is attached to the opening 101 a of the device main body 101 so as to be openable and closable. The inner space S is a space surrounded by the device main body 101 and the door member 102.

Note that, the device main body 101 and the door member 102 may have a commonly known heat insulation structure. Moreover, the device main body 101 has the opening 101 a in a side surface of the device main body 101 in the figure, but there is no limitation thereto and the device main body 101 may have an opening in an upper surface thereof.

The device main body 101 has a placement portion 103, on which the cold insulator I is placed, in a lower part of the inner space S. In the cooling device 1 of the present embodiment, the temperature sensor 20 and a mass sensor (a weighing means) 104 are provided in the placement portion 103.

The temperature sensor 20 measures a temperature of the cold insulator I placed on the placement portion 103. The temperature sensor 20 is a sensor of a contact type that measures the temperature of the cold insulator I by contacting the cold insulator I. For example, the temperature sensor 20 has a probe in an upper surface of the placement portion 103 and detects the temperature of the cold insulator I that contacts the probe.

For example, the temperature sensor 20 outputs a discrete measurement result to the control unit 30. An interval at which the temperature sensor 20 measures the temperature is able to be appropriately set by a user of the cooling device 1.

The mass sensor 104 measures mass of the cold insulator I placed on the placement portion 103.

The cooling unit 108 is provided, for example, in the device main body 101 and cools the inner space S on the basis of a control signal input from the control unit 30. As the cooling unit 108, a commonly known configuration is able to be adopted and examples thereof include a cooling unit of a compressor system and a cooling unit of a Peltier system. Moreover, a cooling method using the cooling unit 108 is able to adopt a commonly known method and examples thereof include a fan type and a direct cooling type.

The control unit 30 transmits a control signal to the cooling unit 108 on the basis of measurement results of the temperature sensor 20 and the mass sensor 104 and controls a temperature of the inner space S. A specific control method will be described later. The control unit 30 may have a monitor 31 in which various measurement results or calculation results are displayed.

Additionally, the cooling device 1 may have an alarm portion 109 that outputs alarm sound under a given condition.

FIGS. 3 to 6 are explanatory views for explaining control of the inner space S based on the temperature of the cold insulator I.

(Case where Cold Insulator I is Excessively Cooled)

FIG. 3 is an explanatory view illustrating an example of a change in the temperature of the cold insulator I when the cold insulator I is cooled by using a conventional cooling device. FIG. 3 is a graph illustrating a correspondence relationship between a cooling time of the cold insulator I and the temperature of the cold insulator I. In FIG. 3, a horizontal axis indicates the cooling time and a vertical axis indicates the temperature of the cold insulator I.

First, it is supposed that the cold insulator I with a temperature T is cooled as illustrated in FIG. 3. It is assumed that the temperature T is, for example, a normal temperature and a phase change material with the temperature T presents a liquid phase. It is also assumed that a melting temperature of the phase change material contained in the cold insulator I is a temperature Tb.

When the cold insulator I illustrated in the figure is cooled by the conventional cooling device set to a temperature (temperature Tx) that is sufficiently low to solidify the cold insulator I, the temperature of the cold insulator I is reduced from the temperature T to the temperature Tx. In the phase change material in the liquid phase, each of molecules of the phase change material freely moves around, but motion thereof becomes weak as the temperature is reduced, and the phase change material is gradually solidified (solidified, crystallized).

At this time, there is a case where, even when the temperature of the phase change material is reduced to the melting temperature of the phase change material, solidification of the phase change material does not start and the temperature is further reduced. Such a phenomenon is known as “excessive cooling”. FIG. 3 illustrates a state where, when the cold insulator I with the temperature T is cooled, the temperature of the cold insulator I is below the melting temperature Tb and is reduced to a temperature Ta at a time t1 (from a time t0 to the time t1).

The temperature of the cold insulator I is reduced to the temperature Ta and then changes to rise. This is a phenomenon caused because the phase change material of the cold insulator I starts to be solidified and releases latent heat. The temperature of the cold insulator I rises until reaching the melting temperature Tb of the phase change material at a time t2 (from the time t1 to the time t2).

The temperature Ta corresponds to a “temperature at which solidification starts” in the invention. Moreover, a difference between the melting temperature Tb and the temperature Ta corresponds to solidification heat of the phase change material contained in the cold insulator I.

The cold insulator I whose temperature reaches the melting temperature Tb makes the solidification of the phase change material progress while keeping the melting temperature Tb (from the time t2 to a time t3). During a period from the time t1 to the time t3, the phase change material of the cold insulator I has a solid phase and the liquid phase mixed.

After the solidification of the phase change material ends (time t2) and all the phases of the phase change material become the solid phase, the temperature of the cold insulator I starts to be reduced again. The temperature of the cold insulator I is reduced to the temperature Tx that is a setting temperature of the cooling device.

In this manner, when the cold insulator I is cooled by the conventional cooling device, the cold insulator I is cooled to the temperature Tx that is the setting temperature of the cooling device and is kept at this temperature.

On the other hand, when the phase change material contained in the cold insulator I melts, the cold insulator I is kept so as to be fixed at the melting temperature of the phase change material. Therefore, the cold insulator I is suitably used when a temperature of a cold insulation object is kept at the melting temperature of the phase change material contained in the cold insulator I.

Thus, when the cold insulator I is cooled by the conventional cooling device, the cold insulator I that is taken out from the cooling device has the temperature that is lower than a temperature at which the cold insulator I is suitably used, so that it is necessary to wait until the temperature of the cold insulator I reaches the melting temperature of the phase change material.

On the other hand, the cooling device 1 of the present embodiment measures the temperature of the cold insulator I by using the temperature sensor 20, and, on the basis of a result of the measurement, the control unit 30 controls the temperature of the inner space S.

FIG. 4 is an explanatory view illustrating an example of a change in the temperature of the cold insulator I when the cold insulator I is cooled by using the cooling device 1 of the present embodiment. FIG. 4 is a graph illustrating a correspondence relationship between a cooling time of the cold insulator I and the temperature of the cold insulator I and is a view corresponding to FIG. 3. In FIG. 4, a horizontal axis indicates the cooling time and a vertical axis indicates the temperature of the cold insulator I.

As illustrated in the figure, the control unit 30 sets a setting temperature of the inner space S to the temperature Tx that is lower than the temperature Ta at which the phase change material of the cold insulator I starts to be solidified, and controls the cooling unit 108 to control the temperature of the inner space S. The temperature Tx corresponds to a “first setting temperature” in the invention.

The temperature of the cold insulator I stored in the inner space S of the cooling device 1 is reduced from the temperature T to the temperature Tx. The temperature of the cold insulator I is reduced to the temperature Ta that is a temperature at which the phase change material used for the cold insulator I starts to be solidified, and then changes to rise and is increased to the melting temperature Tb.

After the solidification of the phase change material that the cold insulator I has ends (time t3) and all the phases of the phase change material become the solid phase, the temperature of the cold insulator I starts to be reduced again. The control unit 30 obtains respective temperatures needed for control of the cooling device 1 as described below on the basis of the measurement result by the temperature sensor 20.

In the cooling device 1, the temperature of the cold insulator I is measured by the temperature sensor 20. The control unit 30 obtains a change amount of the temperature of the cold insulator I per unit time by using the interval at which the temperature sensor 20 measures the temperature and the measurement result acquired from the temperature sensor 20. That is, the control unit 30 obtains a slope of a tangent of each measurement time in the graph illustrated in FIG. 4. The “interval at which the temperature sensor 20 measures the temperature” corresponds to a “unit time” in the present specification.

The control unit 30 is able to obtain the temperature Ta and the melting temperature Tb from the change amount that is obtained. That is, the control unit 30 is able to obtain, as the temperature Ta, a temperature at a measurement time where the change amount that is obtained turns over from negative to positive.

Moreover, when it is possible to determine that the change amount that is obtained is equal to or less than a predefined reference and the temperature of the cold insulator I does not change and when a state where the cold insulator I does not change in the temperature continues for a predefined period or more, the control unit 30 is able to obtain this temperature as the melting temperature Tb.

At this time, when the measurement temperature of the cold insulator I is within a predefined variation range, the control unit 30 may determine that “the cold insulator I does not change in the temperature”. For example, when the cooling unit 108 is a cooling unit of a compressor system, the temperature of the inner space S periodically changes and is difficult to be in a stable state in some cases. Such a phenomenon is known as so-called “hunting”.

In the cooling device 1 using the cooling unit of the compressor system, reduction of the temperature during the hunting may be erroneously recognized as reduction of the temperature when the solidification of the cold insulator I ends and the temperature of the cold insulator I starts to be reduced again. Thus, the variation range of the temperature due to the hunting may be estimated in advance, and when the change in the temperature of the cold insulator I is within the variation range, it may be determined that the cold insulator I does not change in the temperature.

Note that, when the cooling unit 108 of the compressor system is used, the control unit 30 may control the cooling unit 108 by so-called PID control to suppress the hunting.

Moreover, from the temperature Ta and the melting temperature Tb that are obtained as described above, the control unit 30 is able to obtain solidification heat (Tb−Ta) of the phase change material used for the cold insulator I.

When detecting the solidification heat of the cold insulator I and the melting temperature Tb on the basis of the measurement result of the temperature sensor 20 as described above and then further detecting that the temperature of the cold insulator I reaches a reference temperature Tr that is lower than the melting temperature Tb, the control unit 30 may set the temperature of the inner space S again (time t4).

That is, when detecting that the temperature of the cold insulator I reaches the reference temperature Tr, the control unit 30 performs control to change the setting temperature of the inner space S from the temperature Tx to a temperature Ty that is higher than the temperature Tx and lower than the melting temperature Tb. The temperature Ty corresponds to a “second setting temperature” in the invention.

The temperature Ty may be appropriately set by the control unit 30 with use of the temperature Tx that is an initial setting temperature and the melting temperature Tb that is obtained or may be set by the user.

After changing the setting temperature of the inner space S to the temperature Ty, the control unit 30 may output alarm sound from the alarm portion 109. This makes it possible for the user of the cooling device 1 to indirectly know the temperature of the inner space S.

The control unit 30 controls the cooling unit 108 to control the temperature of the inner space S to be the temperature Ty.

FIG. 4 indicates that the temperature Ty is a temperature that is lower than the reference temperature Tr, but there is no limitation thereto. For example, the temperature Ty is only required to be equal to or more than the reference temperature Tr and smaller than the melting temperature Tb (Tr≤Ty<Tb).

In the cooling device 1 in which the temperature of the inner space S is set again to Ty, the temperature of the inner space S rises from the temperature Tx to the temperature Ty. Accordingly, the temperature of the cold insulator I is also cooled to the temperature Ty and is kept at this temperature.

(Case where Cold Insulator I is not Excessively Cooled)

FIG. 5 is an explanatory view illustrating an example of a change in the temperature of the cold insulator I when the cold insulator I is cooled by using the conventional cooling device and is a view corresponding to FIG. 3. FIG. 5 is a graph illustrating a correspondence relationship between a cooling time of the cold insulator I and the temperature of the cold insulator I. In FIG. 5, a horizontal axis indicates the cooling time and a vertical axis indicates the temperature of the cold insulator I.

First, it is supposed that the cold insulator I with the temperature T is cooled as illustrated in FIG. 5. When the cold insulator I illustrated in the figure is cooled by the conventional cooling device set to a temperature (temperature Tx) that is sufficiently low to solidify the cold insulator I, the temperature of the cold insulator I is reduced from the temperature T to the temperature Tx. In the phase change material in the liquid phase, each of molecules of the phase change material freely moves around, but motion thereof becomes weak as the temperature is reduced, and the phase change material is gradually solidified (solidified, crystallized).

The cold insulator I whose temperature reaches the melting temperature Tb makes solidification of the phase change material progress while keeping the melting temperature Tb (from a time t2 to a time t3). During a period from the time t2 to the time t3, the phase change material of the cold insulator I has the solid phase and the liquid phase mixed.

After the solidification of the phase change material ends (time t3) and all the phases of the phase change material become the solid phase, the temperature of the cold insulator I starts to be reduced again. The temperature of the cold insulator I is reduced to the temperature Tx that is the setting temperature of the cooling device.

In this manner, when the cold insulator I is cooled by the conventional cooling device, the cold insulator I is cooled to the temperature Tx that is the setting temperature of the cooling device and is kept at this temperature.

With respect to such a cold insulator I, the cooling device 1 of the present embodiment measures the temperature of the cold insulator I by using the temperature sensor 20, and, on the basis of a result of the measurement, the control unit 30 controls the temperature of the inner space S.

FIG. 6 is an explanatory view illustrating an example of a change in the temperature of the cold insulator I when the cold insulator I is cooled by using the cooling device 1 of the present embodiment and is a view corresponding to FIG. 4. In FIG. 6, a horizontal axis indicates the cooling time and a vertical axis indicates the temperature of the cold insulator I.

First, the control unit 30 sets the setting temperature of the inner space S to the temperature Tx that is lower than the melting temperature Tb of the cold insulator I and controls the cooling unit 108 to control the temperature of the inner space S. The temperature of the cold insulator I stored in the inner space S of the cooling device 1 is reduced from the temperature T to the temperature Tx. When the temperature of the phase change material used for the cold insulator I reaches the melting temperature Tb, the temperature of the cold insulator I is kept so as to be fixed at the melting temperature Tb.

After the solidification of the phase change material that the cold insulator I has ends (time t3) and all the phases of the phase change material become the solid phase, the temperature of the cold insulator I starts to be reduced again.

At this time, when detecting the melting temperature Tb of the cold insulator I on the basis of the measurement result of the temperature sensor 20 as described above and then further detecting that the temperature of the cold insulator I reaches the reference temperature Tr that is lower than the melting temperature Tb, the control unit 30 may set the temperature of the inner space S again (time t4).

That is, when detecting that the temperature of the cold insulator I reaches the reference temperature Tr, the control unit 30 performs control to change the setting temperature of the inner space S from the temperature Tx to the temperature Ty that is higher than the temperature Tx and lower than the melting temperature Tb. The temperature Ty corresponds to the “second setting temperature” in the invention.

The control unit 30 controls the cooling unit 108 to control the temperature of the inner space S to be the temperature Ty. In the cooling device 1 in which the temperature of the inner space S is set again to Ty, the temperature of the inner space S rises from the temperature Tx to the temperature Ty. Accordingly, the temperature of the cold insulator I is also cooled to the temperature Ty and is kept at this temperature.

FIG. 6 indicates that the temperature Ty is a temperature that is lower than the reference temperature Tr, but there is no limitation thereto. For example, the temperature Ty is only required to be equal to or more than the reference temperature Tr and smaller than the melting temperature Tb (Tr≤Ty<Tb).

After changing the temperature of the inner space S to the temperature Ty so that the temperature of the inner space S reaches the temperature Ty, the control unit 30 may output alarm sound from the alarm portion 109 (time t5). This makes it possible for the user of the cooling device 1 to indirectly know the temperature of the inner space S.

Moreover, after changing the temperature of the inner space S to the temperature Ty so that the temperature of the cold insulator I reaches the temperature Ty, the control unit 30 may output alarm sound from the alarm portion 109 (time t6). This makes it possible for the user of the cooling device 1 to indirectly know the temperature of the cold insulator I.

According to the cooling device 1 having a configuration as described above, it is possible to appropriately cool and solidify the cold insulator I and to keep the cold insulator I at the temperature Ty that is higher than the temperature Tx at which the cold insulator I is solidified. Thus, as compared to a case where the cold insulator I is kept at the temperature Tx, the temperature of the cold insulator I reaches the melting temperature of the phase change material in a short time and the cold insulator I that is taken out from the cooling device 1 is able to be used early at an appropriate temperature.

Moreover, in the cooling device 1 having the aforementioned configuration, after the solidification of the phase change material that the cold insulator I has ends (after the time t3 elapses), the temperature of the inner space S rises to the temperature Ty under control that is defined in advance. The control is performed on the basis of a measurement value differently from a case where the temperature of the inner space S is raised in accordance with an empirical rule, so that the temperature rise control from the time t3 is easily performed in a short time.

Moreover, in the cooling device 1 having the aforementioned configuration, the temperature of the inner space S is controlled on the basis of an actual measurement value of the temperature of the cold insulator I, so that temperature control is able to be performed reliably even when a type of the cold insulator I changes.

As a result, according to the cooling device 1 having the configuration as described above, the cold insulator I that is taken out from the cooling device 1 is able to be used early at an appropriate temperature.

Note that, in the cooling device 1 of the present embodiment, the control unit 30 may be allowed to change the interval at which the temperature sensor 20 measures the temperature. For example, when the cold insulator I having the same size and the same type is repeatedly cooled, times t1 to t6 during which the cold insulator I is cooled are able to be predicted and approximated in accordance with the initial temperature T. In such a case, the temperature of the cold insulator I may be measured with a small measurement interval at a time near times predicted as the times t1 to t6 and the temperature of the cold insulator I may be measured with a wide interval at a time other than the time.

Moreover, the control unit 30 may predict the change in the temperature of the cold insulator I on the basis of the mass of the cold insulator I, which is weighed by the mass sensor 104. In a case where the control unit 30 knows the change in the temperature of the cold insulator I when the cold insulator I with the temperature T is cooled by using the cooling device 1 in which the temperature of the inner space S is the temperature Tx, the control unit 30 is able to approximate the change in the temperature per unit mass of the cold insulator I in accordance with specific heat of the cold insulator I and approximate the times t1 to t6 for the cold insulator I of unit mass. Approximate values of the times t1 to t6 correspond to an “expected cooling time per unit mass” in the invention.

On the basis of the expected cooling time per unit mass of the cold insulator I, which is stored in advance, and a weighing result of the mass sensor 104, the control unit 30 is able to approximate the expected cooling time of a whole of the cold insulator I stored in the inner space S. In accordance with the expected cooling time obtained from the mass of the cold insulator I as described above, the control unit 30 may cause the temperature of the cold insulator I to be measured with a small measurement interval at a time near the times predicted as the times t1 to t6 and cause the temperature of the cold insulator I to be measured with a wide interval at a time other than the time.

The control unit 30 may display, in the monitor 31, the “expected cooling time of the whole of the cold insulator I” that is obtained.

Moreover, in the present embodiment, the control unit 30 performs control to change the setting temperature of the inner space S from the temperature Tx to the temperature Ty after detecting that the temperature of the cold insulator I reaches the reference temperature Tr that is lower than the melting temperature Tb, but there is no limitation thereto.

For example, the control unit 30 may perform control to change the setting temperature of the inner space S from the temperature Tx to the temperature Ty without waiting after detecting that the temperature of the cold insulator I starts to be reduced again. By performing such control, the control unit 30 is able to control the temperature of the inner space S without waiting from the time t3 to the time t4 in FIGS. 4 and 6. Thus, the cooling device 1 that performs such control enables to shorten a time required until the cold insulator I is allowed to be used.

Moreover, the control unit 30 may perform control to change the setting temperature of the inner space S from the temperature Tx to the temperature Ty when a reference time that is set in advance elapses after detecting that the temperature of the cold insulator I starts to be reduced again. When the control unit 30 performs such timer control, the control is facilitated.

Moreover, in the present embodiment, the sensor of the contact type that measures the temperature of the cold insulator I by contacting the cold insulator I is used as the temperature sensor 20 to directly measure the temperature of the cold insulator I, but there is no limitation thereto.

For example, the probe of the temperature sensor 20 may be made proximate to the cold insulator I to a degree of not contacting the cold insulator I to measure an ambient temperature, and on the basis of a result of the measurement, solidification heat of the cold insulator I may be indirectly detected. Moreover, by making a heat transfer jig formed by a substance having high heat conductivity proximate to the cold insulator I and measuring a temperature of the heat transfer jig, the solidification heat of the cold insulator I may be indirectly detected.

Second Embodiment

FIG. 7 is an explanatory view of a cooling device 2 according to a second embodiment of the invention. The cooling device 2 of the present embodiment is partly the same as the cooling device 1 of the first embodiment. A component of the following embodiment, which is common to that of the first embodiment, will be given the same reference sign and detailed description thereof will be omitted.

The cooling device 2 has the cooling portion 10, a temperature sensor (a measurement means) 21, and the control unit (the control means) 30.

The device main body 101 has a plurality of placement portions 103 (three placement portions 103 in FIG. 7), on each of which the cold insulator I is placed, in the inner space S. In the cooling device 1 of the present embodiment, the temperature sensor 21 is provided in each of the placement portions 103.

The temperature sensor 21 is provided in the placement portion 103 and measures the temperature of the cold insulator I stored in the inner space S. The temperature sensor 21 is a sensor of a contact type that measures the temperature of the cold insulator I by contacting the cold insulator I. The temperature sensor 21 has a plurality of probes 211 in an upper surface of the placement portion 103 and detects temperatures of cold insulators I in contact with the respective probes 211.

For example, the temperature sensor 21 outputs, to the control unit 30, measurement results of the cold insulators I detected by the plurality of probes 211. The control unit 30 detects each of temperatures of a plurality of cold insulators I and obtains a temperature profile for each of the cold insulators I as in FIG. 4 or 6 of the first embodiment described above.

The control unit 30 may set the temperature of the inner space S again after detecting the reference temperature Tr for all of the plurality of cold insulators I. In this case, after changing the temperature of the inner space S to the temperature Ty so that the temperatures of all the cold insulators I reach the temperature Ty, the control unit 30 may output alarm sound from the alarm portion 109. This makes it possible for the user of the cooling device 1 to indirectly know the temperatures of the cold insulators I.

According to the cooling device 2 having a configuration as described above, it is possible to appropriately cool and solidify the plurality of cold insulators I and to keep the cold insulators I at the temperature Ty that is higher than the temperature Tx at which the plurality of cold insulators I are solidified. Accordingly, the plurality of cold insulators I that are taken out from the cooling device 2 are able to be used early at an appropriate temperature.

In the foregoing description, a case where temperatures at the plurality of placement portions 103 (three placement portions 103 in FIG. 7) for placement are integrally managed as the temperature of the inner space S has been described, but the present embodiment is not limited thereto. In the present embodiment, each of the plurality of placement portions 103 may be provided with the temperature sensor 21 and the temperature of the inner space S may be managed by the control unit 30 for each of the placement portions 103.

Note that, the plurality of placement portions 103 may be arranged, for example, in a vertical direction in the inner space S to constitute three hierarchy floors as illustrated in FIG. 7. For example, it is assumed that the temperatures of all cold insulators I in each of the floors reach the reference temperature Tr in FIG. 7 in order of the middle placement portion 103, the uppermost placement portion 103, and the lowermost placement portion 103.

In this case, first, after detecting the reference temperature Tr for all the cold insulators I placed on the middle placement portion 103, the control unit 30 sets the temperature at the middle placement portion 103 again. The control unit 30 changes the temperature at the middle placement portion 103 to the temperature Ty.

After the temperatures of all the cold insulators I placed on the middle placement portion 103 reach the temperature Ty, alarm sound may be output from the alarm portion 109. This makes it possible for the user of the cooling device 1 to indirectly know the temperatures of the cold insulators I placed on the middle placement portion 103.

Next, after detecting the reference temperature Tr for all the cold insulators I placed on the uppermost placement portion 103, the control unit 30 sets the temperature at the uppermost placement portion 103 again. The control unit 30 changes the temperature at the uppermost placement portion 103 to the temperature Ty.

After the temperatures of all the cold insulators I placed on the uppermost placement portion 103 reach the temperature Ty, alarm sound may be output from the alarm portion 109. This makes it possible for the user of the cooling device 1 to indirectly know the temperatures of the cold insulators I placed on the uppermost placement portion 103.

Next, after detecting the reference temperature Tr for all the cold insulators I placed on the lowermost placement portion 103, the control unit 30 sets the temperature at the lowermost placement portion 103 again. The control unit 30 changes the temperature at the lowermost placement portion 103 to the temperature Ty.

After the temperatures of all the cold insulators I placed on the lowermost placement portion 103 reach the temperature Ty, alarm sound may be output from the alarm portion 109. This makes it possible for the user of the cooling device 1 to indirectly know the temperatures of the cold insulators I placed on the lowermost placement portion 103.

Note that, the alarm sound that is output after the temperatures of all the cold insulators I placed on the placement portion 103 reach the temperature Ty may be differentiated between the floors. This makes it possible for the user of the cooling device 1 to indirectly know the temperatures of the cold insulators I placed on the placement portion 103 in each of the floors.

In this manner, the temperature at each of the placement portions 103 is set again by the control unit 30 and a timing when the user is allowed to use the cold insulators I in each of the floors is able to be notified by alarm sound or the like. As a result, for example, the cold insulators I that are included in the lowermost placement portion 103 and are frozen lastly and the cold insulators I included in the other (the uppermost and middle) placement portions 103 are separately managed as described above.

When the temperature of the inner space S is managed by the control unit 30 for each of the placement portions 103 as described above, without being affected by the cold insulators I that are frozen lastly in a whole of the inner space S, the cold insulators I included in the placement portion 103 in the floor where the cold insulators that are frozen lastly are not included are able to be frozen. Thus, it is possible to prevent that the cold insulators I included in the placement portion 103 in the floor where the cold insulators that are frozen lastly are not included are continuously kept at a temperature for freezing even though being already frozen.

Third Embodiment

FIG. 8 is an explanatory view of a cooling device 3 according to a third embodiment of the invention. The cooling device 2 has the cooling portion 10, temperature sensors (measurement means) 20 and 22, and the control unit (the control means) 30.

The temperature sensor 22 is provided in the placement portion 103. The temperature sensor 22 measures a temperature of a reference material Ref placed on the placement portion 103. As the reference material Ref, one in which a reference substance is liquid-tightly sealed in a pouch-like container is adopted. As the reference substance, a substance that is liquid at a normal temperature and does not change in a phase in a temperature range where setting for the inner space S is allowed is adopted. The temperature of the reference material Ref, which is measured by the temperature sensor 22, corresponds to a “temperature corresponding to a temperature of an object” in the invention.

A container used for the reference material Ref and the container used for the cold insulator I are preferably the same. Moreover, it is assumed that mass and specific heat of the reference substance, a surface area of the container that seals the reference substance, and heat conductivity, which are used for the reference material Ref, are known.

The cooling device 3 performs cooling with the reference material Ref placed on the placement portion 103 together with the cold insulator I. The control unit 30 measures the temperature of the reference material Ref by using the temperature sensor 22 and obtains a change in the temperature of the reference material Ref and a time required for the temperature change. On the basis of a measurement result that is obtained, the mass and the specific heat of the reference substance, the surface area of the container that seals the reference substance, and the heat conductivity, the control unit 30 is able to obtain a quantity of heat released from the reference material Ref. Further, the control unit 30 is able to obtain a quantity of heat released from the reference material Ref per unit time.

On the other hand, the control unit 30 measures the temperature of the cold insulator I by using the temperature sensor 20. The cold insulator I is cooled in the same environment (inner space S) as that of the reference material Ref. Therefore, the “quantity of heat released from the reference material Ref per unit time” obtained as described above is considered to be the same as a “quantity of heat released from the cold insulator I per unit time”.

Thus, when a quantity of latent heat of the cold insulator I is known, a “time required for the cold insulator I to release the latent heat” is able to be obtained from the “quantity of the latent heat” and the “quantity of the heat released from the cold insulator I per unit time”. The time corresponds to an elapsed time between the time t2 and the time t3 in FIGS. 4 and 6.

According to the cooling device 3 as described above, the cold insulator I that is taken out from the cooling device 1 is able to be used early at an appropriate temperature. Moreover, it is possible to approximate a length of a period (period between the time t2 and the time t3) in which the cold insulator I keeps the melting temperature Tb during cooling and to predict a time required for the cold insulator I to be frozen.

Fourth Embodiment

FIG. 9 is an explanatory view of a cooling device 4 according to a fourth embodiment of the invention. The cooling device 2 has the cooling portion 10, an imaging device (a measurement means) 25, and the control unit (the control means) 30.

The imaging device 25 is provided in the inner space S and captures an image of the cold insulator I stored in the inner space S. As the imaging device 25, a known infrared thermography camera is able to be used. The imaging device 25 is used as a temperature sensor of a non-contact type.

The control unit 30 measures the temperature of the cold insulator I on the basis of the image captured by the imaging device 25 and adjusts the setting temperature of the inner space S on the basis of a result of the measurement. As a method of adjusting the setting temperature of the inner space S, a method described in the first embodiment is able to be adopted.

According to the cooling device 4 as described above, the cold insulator I that is taken out from the cooling device 1 is able to be used early at an appropriate temperature.

Fifth Embodiment

FIGS. 10 and 11 are explanatory views of a cooling device 5 according to a fifth embodiment of the invention. The cooling device 5 has a cooling portion 11, the imaging device (the measurement means) 25, and the control unit (the control means) 30.

The cooling portion 11 has the inner space S in which the cold insulator I to be cooled is stored. The cooling portion 11 has a device main body 111, a door member 112, and a cooling unit (a cooling means) 118.

The device main body 111 has the inner space S. The inner space S is a space surrounded by the device main body 111 and the door member 112.

The device main body 111 has a placement portion 105 (a moving means), which extends in a horizontal direction, in a center part of the inner space S. The placement portion 105 spatially divides the inner space S into a first space S1 that is in an upper part of the device and a second space S2 that is different from the first space S1 and is in a lower part of the device. The placement portion 105 is openable and closable in a center part.

The door member 112 has a first door member 112 a that closes an opening of the device main body 111 on the first space S1 side and a second door member 112 b that closes an opening of the device main body 111 on the second space S2 side. The first door member 112 a and the second door member 112 b are openable and closable independently.

The imaging device 25 is provided at a position where an image of an inside of the first space S1 is able to be captured.

The cooling unit 118 has a first unit 118 a and a second unit 118 b. The cooling unit 118 is provided in the device main body 111 and cools the inner space S on the basis of a control signal input from the control unit 30. At this time, the first unit 118 a is provided on the first space S1 side and used for cooling of the first space S1. Moreover, the second unit 118 b is provided on the second space S2 side and used for cooling of the second space S2.

In the cooling device 5 as described above, first, the first door member 112 a is opened so that the cold insulator I is stored in the first space S1 as illustrated in FIG. 10. The first space S1 is controlled to have the temperature Tx by the first unit 118 a, similarly to the cooling device 1 indicated in the first embodiment described above.

The control unit 30 uses the imaging device 25 to measure the temperature of the cold insulator I stored in the first space S1 and changes a setting temperature of the first space S1 to the temperature Ty on the basis of a result of the measurement. As a method of adjusting the setting temperature of the first space S1, a method described in the first embodiment is able to be adopted.

On the other hand, the control unit 30 controls, by the second unit 118 b, a temperature of the second space S2 to be at a third setting temperature that is higher than the temperature Tx and lower than the melting temperature Tb. The temperature of the second space S2 may be the temperature Ty. That is, the third setting temperature may be the same as or different from the second setting temperature.

The control unit 30 opens an opening 105 a of the placement portion 105 after detecting that the temperature of the cold insulator I reaches the temperature Ty (time t6). As illustrated in FIG. 11, the cold insulator I falls from the opening 105 a to be moved to the second space S2 and stored in the second space S2.

A different cold insulator I is able to be stored in the first space S1 and the cold insulator I is able to be solidified. The cold insulator I stored in the second space S2 is taken out from the cooling portion 11 by using the second door member 112 b and used for cold insulation.

According to the cooling device 5 as described above, the cold insulator I that is taken out from the cooling device 1 is able to be used early at an appropriate temperature.

Moreover, in the cooling device 5, a space (first space S1) in which the cold insulator I is solidified and a space (second space S2) in which the cold insulator I that is solidified and is in a state of being able to be used is kept are different. Thus, in the cooling device 5, the different cold insulator I that is being solidified in the first space S1 is less likely to be affected by a temperature change caused by opening and closing of the door when the cold insulator I kept in the second space S2 is taken out. Thus, in the cooling device 5, the temperature of the cold insulator I that is being solidified is easily measured and managed and temperature control of the first space S1 is facilitated.

Sixth Embodiment

FIG. 12 is an explanatory view of a cooling device 6 according to a sixth embodiment of the invention. The cooling device 6 is different from the cooling device 5 of the fifth embodiment in a way of dividing the inner space S.

The cooling device 6 has a cooling portion 12, the imaging device (the measurement means) 25, and the control unit (the control means) 30.

The cooling portion 12 has the inner space S in which the cold insulator I to be cooled is stored. The cooling portion 12 has the device main body 111, the door member 112, and the cooling unit (the cooling means) 118.

The device main body 121 has the inner space S. The inner space S is a space surrounded by the device main body 121 and the door member 122.

The device main body 121 has a partition portion 106, which extends in a vertical direction, in a center part of the inner space S. The partition portion 106 spatially divides the inner space S into the first space S1 that is in a left part of the device and the second space S2 that is different from the first space S1 and is in a right part of the device. The partition portion 106 is openable and closable in a lower end part.

The device main body 121 further has a placement portion (a moving means) 107 on which the cold insulator I is placed. The placement portion 107 has a not-illustrated driving portion and is movable between the first space S1 and the second space S2. As such a placement portion 107, a commonly known moving stage or the like is able to be used. Moreover, as the placement portion 107, a known conveyance device is able to be adopted.

The door member 122 has a first door member 122 a that closes an opening of the device main body 121 on the first space S1 side and a second door member 122 b that closes an opening of the device main body 121 on the second space S2 side. The first door member 122 a and the second door member 122 b are openable and closable independently.

The imaging device 25 is provided at a position where an image of an inside of the first space S1 is able to be captured.

The cooling unit 118 has the first unit 118 a and the second unit 118 b. The cooling unit 118 is provided in the device main body 121 and cools the inner space S (the first space S1 and the second space S2) on the basis of a control signal input from the control unit 30, similarly to the cooling device 5 described above.

In the cooling device 6 as described above, temperature control for the first space S1 and the second space S2 is performed similarly to the cooling device 5 described above.

The control unit 30 opens a lower end 106 a of the partition portion 106 after detecting that the temperature of the cold insulator I reaches the temperature Ty (time t6). Moreover, the control unit 30 moves the cold insulator I from the first space S1 to the second space S2 by using the placement portion 107.

According to the cooling device 6 as described above, the cold insulator I that is taken out from the cooling device 1 is able to be used early at an appropriate temperature. Moreover, in the cooling device 6, the temperature of the cold insulator I that is being solidified is easily measured and managed and temperature control for the first space S1 is facilitated.

In the embodiment described so far, the space S2 in which the frozen cold insulator I is kept is desirably designed so that the space S2 has heat capacity sufficiently larger than heat capacity of the cold insulator to be kept. As a result, reduction of an ambient temperature in the space S2, which is caused by inputting the cold insulator I, is able to be suppressed as much as possible.

Hereinbefore, preferred embodiments according to the invention have been described with reference to the accompanying drawings, but it goes without saying that the invention is not limited to the examples. The shapes, the combinations, and the like of respective components in the examples described above are merely examples, and may be modified in various manners on the basis of a design requirement within a range not departing from a scope of the invention. 

1. A cooling device comprising: a cooling portion that has an inner space storing an object; a measurement means of measuring a temperature corresponding to a temperature of the object stored in the inner space; and a control means of controlling a temperature of the inner space based on a measurement result by the measurement means, wherein based on the measurement result, the control means performs control to change the temperature of the inner space from a first setting temperature that is lower than a temperature at which the object in a liquid phase starts to be solidified to a second setting temperature that is higher than the first setting temperature and lower than a melting temperature of the object.
 2. The cooling device according to claim 1, wherein when detecting solidification heat and the melting temperature of the object based on the measurement result and then further detecting that the measurement result reaches a reference temperature that is a temperature lower than the melting temperature, the control means performs control to change the temperature of the inner space from the first setting temperature to the second setting temperature.
 3. The cooling device according to claim 1, wherein when detecting the melting temperature based on the measurement result and then further detecting that the measurement result reaches a reference temperature that is a temperature lower than the melting temperature, the control means performs control to change the temperature of the inner space from the first setting temperature to the second setting temperature.
 4. The cooling device according to claim 2, wherein the control means acquires the temperature of the object per unit time from the measurement means and detects the solidification heat based on a change amount of the measurement result per unit time.
 5. The cooling device according to claim 1, wherein the control means acquires the temperature of the object per unit time from the measurement means and detects the melting temperature based on a change amount of the measurement result per unit time.
 6. The cooling device according to claim 4, wherein the control means is able to change the unit time.
 7. The cooling device according to claim 1, wherein the cooling portion has a placement portion on which the object is placed, and the measurement means is a temperature sensor of a contact type that is provided in the placement portion.
 8. The cooling device according to claim 7, wherein the temperature sensor has a plurality of probes, and the plurality of probes are provided in the placement portion.
 9. The cooling device according to claim 7, wherein the placement portion has a plurality of placement portions, the plurality of placement portions are arranged in a vertical direction, and a temperature is controlled for each of the placement portions.
 10. The cooling device according to claim 1, wherein the measurement means is a temperature sensor of a non-contact type that is provided in the inner space.
 11. The cooling device according to claim 1, wherein the cooling portion has a placement portion on which the object is placed, the placement portion has a weighing means of weighing mass of the object, and based on an expected cooling time per unit mass of the object, which is stored in advance, and a weighing result of the weighing means, the control means approximates an expected cooling time of a whole of the object stored in the inner space.
 12. The cooling device according to claim 1, wherein the inner space is spatially divided into a first space and a second space that is different from the first space, and has a moving means of moving the object from the first space to the second space, the first space includes the measurement means and is provided so as to be able to change a temperature of the first space between the first setting temperature and the second setting temperature, and the second space is set to have a third setting temperature that is higher than the first setting temperature and lower than the melting temperature of the object.
 13. The cooling device according to claim 1, wherein the cooling portion has a cooling means of cooling the inner space, and the cooling means is a cooling unit of a compressor system.
 14. The cooling device according to claim 1, wherein the cooling portion has a cooling means of cooling the inner space, and the cooling means is a cooling unit of a Peltier system.
 15. The cooling device according to claim 1, comprising an alarm portion that outputs alarm sound, wherein the control means changes the temperature of the inner space to the second setting temperature and then causes the alarm portion to output the alarm sound.
 16. The cooling device according to claim 1, comprising an alarm portion that outputs alarm sound, wherein the control means changes the temperature of the inner space to the second setting temperature, and after the temperature of the inner space reaches the second setting temperature, the control means causes the alarm portion to output the alarm sound.
 17. The cooling device according to claim 1, comprising an alarm portion that outputs alarm sound, wherein the control means changes the temperature of the inner space to the second setting temperature, and after the temperature of the object reaches the second setting temperature, the control means causes the alarm portion to output the alarm sound. 